Problem: Combine like terms to create an equivalent expression. $7.4z-5\left(-1.6z+2.4\right)$
Answer: Use the distributive property to multiply the ${-5}$ into the parentheses. $\phantom=7.4z{-5}\left(-1.6z+2.4\right)$ $=7.4z+({-5})\cdot\left(-1.6z\right)+({-5})\cdot\left(2.4\right)$ $=7.4z+8z-12$ $={7.4}z+8z-12$ $=({7.4}+8)z-12$ $=15.4z-12$ The expanded expression is $15.4z-12$